Mosquito season brings possible West Nile virus infections

Last year’s local and national resurgence of reported West Nile virus cases has officials urging residents to stay alert and protect themselves from the potentially fatal mosquito-borne illness.

By Sarah Lakesarah.lake@doverpost.com@sussex_sarah

Last year’s local and national resurgence of reported West Nile virus cases has officials urging residents to stay alert and protect themselves from the potentially fatal mosquito-borne illness.

“We’d like to say that West Nile virus is not cause for alarm, but rather a cause for concern and due vigilance,” said Bill Meredith, administrator for the Delaware Department of Natural Resources and Environmental Control’s Mosquito Control Section.

According to the Centers for Disease Control and Prevention, throughout the 2012 mosquito season, which typically runs from May through October, Delaware saw nine reported human cases of WNV, one of which was fatal. In 2011, Delaware saw one reported case and in 2010, no reported cases.

This increase was by no means specific to Delaware, as several states saw a similar resurgence. WNV numbers in Texas skyrocketed from 27 reported cases and two deaths in 2011 to 1,868 reported cases and 89 deaths in 2012.

Officials have attributed these increases to hotter than normal temperatures, which Meredith says makes mosquitoes more “viremic,” or more likely to carry a virus.

“Nobody knows across the country what this summer holds in store,” he said. “If we have a repeat of those higher than normal temperatures, we could possibly see another resurgence. So far, we’ve had a far cooler than normal spring, so maybe West Nile virus won’t amplify as much as it did last summer.”

So far this year, four states have reported human cases of WNV. California’s one case was fatal. Mississippi and Tennessee have reported one case each and Texas has reported two cases.

Between 1999, when WNV first hit the U.S., and 2012, the CDC has reported 37,088 human cases across the country. Delaware has seen 32, Maryland 261 and Virginia 121.

According to the CDC, there are no medications to treat or vaccines to prevent WNV infection. Most people infected will have no symptoms. About one in five of those infected will develop a fever with other symptoms, and less than one percent will develop a serious, sometimes fatal neurologic illness, such as encephalitis, which is inflammation of the brain, or meningitis, which is inflammation of the lining of the brain and spinal cord.

While studies have shown that those with weakened immune systems – such as cancer patients or the elderly – are more susceptible to development of neurologic illness due to WNV, local health officials say everyone should be cautious.

Tabatha Offutt-Powell, head of the Delaware Division of Public Health’s Sussex County office of Infectious Disease Epidemiology, said there’s no reason that healthy individuals who contract WNV could not develop severe symptoms.

“Anyone who is going outdoors during peak mosquito-biting hours and are not using DEET repellent or wearing protective clothing are at risk,” Offutt-Powell said. “Mosquitoes don’t discriminate. They go for anyone outdoors.”

For residents who think they have a serious mosquito problem at their home, DNREC provides free services that includes low-volume spraying in neighborhoods, developments, towns and individual rural properties.

“We want people to call us if they are experiencing intolerable numbers of biting mosquitoes,” Meredith said. “We’re one state agency that likes to get yelled at because it allows us to focus our limited resources on certain areas to provide some relief.”

Sussex County and southern Kent County residents should call the Mosquito Control’s Milford office at (302) 422-1512.

Homeowners are urged to eliminate ideal breeding conditions for mosquitoes by draining all sources of standing water, such as buckets, birdbaths, rain barrels, old tires, and other items that collect rain water.

Residents can help monitor WNV by reporting any sick or dead wild birds of certain species to the Mosquito Control’s Milford office. Those species are crows, blue jays, cardinals, robins, hawks and owls, plus clusters of three or more sick or dead birds of any species.